BIOLOGICAL AND OCEANOGRAPHIC OBSERVATIONS 

 IN THE CENTRAL NORTH PACIFIC JULY-SEPTEMBER 1958 



By 



James W. McGary, Oceanographer 



and 



Joseph J. Graham 

 Fishery Research Biologist 

 Honolulu Biological Laboratory 

 Honolulu, Hawaii 



One of the primary objectives of the 

 Honolulu Biological Laboratory's studies of the 

 eilbacore, Thunnus germo (Lacepede)— , has 

 been to determine whether there are albacore 

 in commercial quantities in the central Pacific 

 north of the Hawaiian Islands. A series of ex- 

 ploratory fishing cruises was made by Honolulu 

 Biological Laboratory (subsequently referred 

 to as "HBL") vessels between January 1954 and 

 December 1956. The pattern of the cruises was 

 such that there was geographic coverage of the 

 area during all seasons of the year (Graham 



1957, Shomura and Otsu 1956, and Callaway 

 1957). The results indicated that the only place 

 where albacore concentrations of commercial 

 value occurred was within the area between 

 155°W. and 175''E. longitude from 42° to 48°N. 

 latitude. Here, where previous cruises using 

 longline and trolling gear had been relatively 

 unsuccessful, promising gill-net catches of 

 albacore were made from vessels of the Bureau 

 of Commercial Fisheries' Seattle Biological 

 Laboratory during July-August 1955 salmon 

 surveys. The contrast between gillnetting and 

 other types of fishing was further accentuated 

 by the fact that in the same area and during the 

 sanne period only a few albacore were caught by 

 trolling from an HBL vessel. The John R. 

 Manning (HBL) returned to the area during the 

 summer of 1956 and obtained similar results: 

 good gill -net and poor troll catches. 



These results suggested that the logical 

 next step was a commercial-scale gill -net test 

 with supporting environmental studies to permit 

 a comparison of the catches and conditions with 

 those of previous years. Consequently, a com- 

 mercial vessel was chartered to make a gill- 

 net survey of the area during the summer of 



1958, and a Bureau vessel was assigned to col- 

 lect the supporting scientific information. 



1/ Also known as Germo alalunga 

 (Bonnaterre) , Thunnus alalunga (Grrrelin) , and 

 Gernno germo (Lacepede). 



The research vessel Hugh M. Smith was 

 assigned to the combination oceanographic- 

 biological survey, which included exploratory 

 fishing to define the northern and southern limits 

 of albacore distribution and to test the relative 

 effectiveness of gill -nets, longlines, and trolling 

 gear. HBL scientists aboard the Smith were 

 also to provide the contract vessel with any 

 data that might contribute to the success of the 

 commercial fishing. 



The Smith departed from Honolulu on 

 July 21, 1958, and arrived in the survey areaon 

 July 28, 1958. On September 4, 1958, the sur- 

 vey was ended and the Smith returned to 

 Honolulu on Septennber 9. 



The M/V Paragon was chartered from 

 NorthwestFisheries, Inc., of Seattle, Washington 

 to make the commercial-scale trial of gill- 

 netting. The Paragon is a halibut schooner 

 having an overall length of 90 feet, a beam of 

 19 feet 5 inches, a draft of 9 feet (empty), a 

 maximum speed of 11.0 knots, and a cruising 

 speed of 10. 5 knots. The Paragon participated 

 in exploratory salmon gill -net fishing in the 

 Bering Sea-Aleutian Islands area during the 

 summers of 1955, 1956, and 1957. Infact, it 

 was one of the vessels, while under charter to 

 the Seattle Biological Laboratory, from which 

 good gill -net catches of albacore were made 

 during the summer of 1955. 



The limits of the fishing area given in 

 the Paragon 's contract included all of the area 

 where promising catches had been made during 

 1955 and 1956 that were within the range of fish- 

 ing vessels that might operate out of the Aleutian 

 ports. The western limit was 175°W. longitude 

 and the eastern limit 155°W. The northern and 

 southern limits were 48°N. and 41°N. (see 

 frontispiece). The selection of the actual posi- 

 tions of the gill -net sets within the area was 

 left to the discretion of the Master. Trolling 

 while underway was required during daylight 

 hours both within the contract fishing area and 



